In recent years, there is a great interest in replacing a long time used materials in concrete structure by nanomaterials (NMs) to produce a concrete with novel functions. NMs are used either to replace a part of cement, producing ecological profile concrete or as admixtures in cement pastes. The great reactivity of NMs is attributed to their high purities and specific surface areas. A number of NMs been explored and among of them nanosilica (NS) has been used most extensively.
Nano silica and fly ash are regarded as pozzolanic materials . So, the combined effect depends on the surface area of these materials to react with the hydrated lime . Nano silica combustion is faster than that of that in fly ash.
Nano silica (NS) has a highly reactive surface area for nucleation of CSH gels. This is in contrast to fly ash's pozzolanic reaction that occurs slowly, requiring a longer time to gain strength (56 days compared to the conventional 28 days strength).
In my review paper, I have discussed and compared nanomaterials to conventional supplementary cementitious materials. Citations within this paper provides examples on the hydration process accelerated by NS.
My opinion:
In general, nanoparticles accelerate the hydration of cement, whether these nanoparticles are inert or active, due to the acceleration of the precipitation of the hydration products. Additionally, many of the commercially available nano-silica work as pozzolanic materials (as for silica fume), so it also accelerates the hydration of cement.
Regards
Yes, nanoparticles accelerate the hydration of cement, whether these nanoparticles are inert or active, due to the acceleration of the precipitation of the hydration products. Additionally, many of the commercially available nano-silica work as pozzolanic materials (as for silica fume), so it also accelerates the hydration of cement.
Dear Dr. Mohammed Salah Nasr , Thank you so much for your useful comment.
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